Lennot

highestPrice = 10**10
class Node:
	def __init__(self,idn):
		self.identifier = idn
		self.connections = [] # Tuples of node 's and ints (prices)
		self.cheapest = [highestPrice,highestPrice] #even, odd
		# If moving from a node's odd cost, the flight is free!

nodes, connections = [int(x) for x in input().split(" ")]
notFoundNodes = []
for ni in range(0,nodes):
	newNode = Node(ni)
	notFoundNodes.append(newNode)

for ci in range(0,connections):
	o,t,p = [int(x) for x in input().split(" ")]
	notFoundNodes[o-1].connections.append((notFoundNodes[t-1],p))
  
notFoundNodes[0].cheapest[0] = 0

cheapestTotalPrice = 0

# Djikstra with a few modifications
while True:
	smallestPrice = highestPrice
	smallestPriceNode = []
	
	# Find cheapest node
	for nd in notFoundNodes:
		evenPrice = nd.cheapest[0]
		oddPrice = nd.cheapest[1]
		if evenPrice == -1:
			if oddPrice != -1:
				if oddPrice < smallestPrice:
					smallestPriceNode = [nd,1]
					smallestPrice = oddPrice
		elif oddPrice == -1:
			if evenPrice != -1:
				if evenPrice < smallestPrice:
					smallestPriceNode = [nd,0]
					smallestPrice = evenPrice
		else:
			if oddPrice < evenPrice:
				if oddPrice < smallestPrice:
					smallestPriceNode = [nd,1]
					smallestPrice = oddPrice
			else:
				if evenPrice < smallestPrice:
					smallestPriceNode = [nd,0]
					smallestPrice = evenPrice
					
	# Update connections of cheapest node
	cn = smallestPriceNode[0]
	if cn is notFoundNodes[-1]:
		cheapestTotalPrice = smallestPrice
		break
	oe = (smallestPriceNode[1] + 1) % 2
	for co in cn.connections:
		cost = smallestPrice + co[1] * oe
		target = co[0]
		if target.cheapest[oe] != -1 and target.cheapest[oe] > cost:
			target.cheapest[oe] = cost
			
	# Nullify the current node
	cn.cheapest[smallestPriceNode[1]] = -1
	if cn.cheapest[0] == -1 and cn.cheapest[1] == -1:
		notFoundNodes.remove(cn)

print (cheapestTotalPrice)

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 53, in <module>
    cn = smallestPriceNode[0]
IndexError: list index out of range

Test 7

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 53, in <module>
    cn = smallestPriceNode[0]
IndexError: list index out of range

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 53, in <module>
    cn = smallestPriceNode[0]
IndexError: list index out of range

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 3

Verdict: TIME LIMIT EXCEEDED